Gas-Bubble Disease of Salmonids: A Critical Review
bubbles, gas bubble disease, salmon, salmonids, water quality, wildlife
U.S. Department of the Interior
Technical Papers of the Bureau of Sport Fisheries and Wildlife
Fish maintained in water supersaturated with air reach equilibrium with the gases dissolved in water. These gases in the fish tend to equilibrate to the atmosphere the same as the gases in the water. Gas-bubble disease is characterized by bubbles under the skin, in the fins, tail, mouth, behind the eyeballs, and in the vascular system. Carbon dioxide does not cause gas-bubble disease. Oxygen can cause gas-bubble disease at about 350 percent air saturation, but nitrogen can cause the disease even below 118 percent air saturation. Excess gas in water can be produced by pressure, increase in temperature, and biotic metabolism, and can be reduced by exposure to air. Carbon dioxide and oxygen can be quantitated by titrimetry, while nitrogen analysis requires manometry, gas chromatography, or mass spectrometry. Saturation tables for atmosphere oxygen and nitrogen in water for 0o to 30o C. are presented.